Due to an open hatch... //

The vessel propulsion compartments were flooded with seawater due to what appears to have been human error. According to the Indian newspaper The Hindu, a hatch on the port side of the vessel was left open by accident while Arihant was still in port. Water apparently entered the vessel when it set sail. //

As the lead boat of a new class of submarines and as New Delhi’s first attempt at building an SSBN, Arihant has had its share of problems. Senior Indian Navy sources told The Hindu that Arihant has faced problems from the beginning partly because of “major differences between the Russian-supplied design and indigenous fabrication are said to have left many issues unaddressed satisfactorily.” //

The Indians plan to build three additional Arihant-class vessels for India’s retaliatory second-strike capability. However, Arihant has apparently proven to be far more expensive than anticipated—and technologically far more troublesome than expected. Indeed, the vessel has been in development for more than 30 years.

“It was initially estimated to cost about ₹3000 crore [crore=10 million] for three boats — now the cost of Arihant itself seems to have gone over ₹14,000 crore,” a former high-ranking naval officer told The Hindu.